This problem can be a bit annoying if you’re used to using the scheduled posts feature. But, like with any problem, there is solution, this time a quick and painless one.
Twitter Tools offers the possibility of setting up a default hashtag for your Tweets. Since this feature won’t work with the scheduled post, I took the liberty of seeing how this actually works – and to our luck – it uses custom fields. To be more precise, aktt_hash_meta custom field.
Therefore, when writing a scheduled post, simply add this custom field, and set it’s value to the hashtag you want to use, for example #ivanlistes. Save the post with this custom field added, schedule it, and that’s all there is to it.
It does require a bit more of work, but this way we don’t touch plugin’s original files, and we’re absolutely sure we won’t break something, cause future compatibility issues and so on.

Hi, I tried the method in your post but the hashtag still won’t display for scheduled, the only difference is that I have 3 to 4 hashtag like which i put in the value as
#tag1 #tag2 #tag3 #tag4
does it need a comma between ? Further more the I didn’t save the post I just simple SCHEDULE it after I added the custom field
oh yeah .. I am using wp 3.1.2 and twitter tools version 2.4
It does need the comma between.
A save is not needed after adding a custom field, so that’s not the reason, though.
If the commas are not the reason, maybe the custom field names have changed, I’ll have a look when I catch the time.